<div class="accordion left-nav-tabs" id="accordionParent" >
  <div class="card">
    <div class="card-header" id="headingOne">
      <button class="btn btn-block text-center" type="button" data-toggle="collapse" data-target="#collapseOne" aria-expanded="true" aria-controls="collapseOne">
        系统管理
      </button>
    </div>
    <div id="collapseOne" class="collapse show" aria-labelledby="headingOne" data-parent="#accordionParent">
      <div class="card-body">
        <div class="list-group">
          <a href="javascript:;" [class]="activeItem==menu?'active':''" class="list-group-item"
             (click)="activeItem = menu" *ngFor="let menu of menus|async; trackBy: trackByItems">
          {{menu}}
          </a>
        </div>
      </div>
    </div>
  </div>
</div>
